Longitudinal perspective on the buffering effect of Tai Chi intervention against accumulated perceived stress and its sleep-improving effects among late adolescence

Purpose First-year university students stand at the close of WHO-defined adolescence (10–19 years), in mid-transition: leaving family, entering a new institution, and assuming adult academic and social roles. Stress during adolescence can have consequences that persist into adulthood. Most mental disorders begin by the mid-twenties, while higher levels of adolescent stress predict greater risks of adult anxiety and depression, academic dropout, and lower workforce participation and productivity. The 16-form simplified Tai Chi routine is easy to learn, but direct evidence of its effect in late adolescents is limited. This randomized controlled trial examined its effect on perceived stress and sleep quality. Participants and methods A total of 176 first-year undergraduates, all aged 18 years at baseline, at a university in Hangzhou, China, were randomly allocated 1:1 to a Tai Chi group ( n = 88) or a no-intervention control group ( n = 88). The Tai Chi group practiced the 16-form simplified routine three times weekly for 12 weeks (90 min per session: 30 min of warm-up and 60 min of guided practice); controls maintained their usual lifestyle. Perceived stress (Perceived Stress Scale, PSS-14) and sleep quality (Pittsburgh Sleep Quality Index, PSQI) were assessed before and after the intervention. The primary outcomes (PSS-14 and PSQI global scores at week 12) were analyzed by baseline-adjusted analysis of covariance. Results The groups had similar baseline characteristics. All 176 participants completed the PSS-14 and 168 had complete PSQI data. Within groups, both measures improved under Tai Chi (PSS-14 −3.28; PSQI −1.00; both P < 0.01), whereas perceived stress rose in controls (+4.47, P < 0.001) and sleep quality was unchanged. After baseline adjustment, PSS-14 scores were lower in the Tai Chi group (adjusted mean difference −7.48, 95% CI −8.80 to −6.17; P < 0.001), as were PSQI global scores (−1.17, 95% CI −1.87 to −0.46; P = 0.001). Exploratory component analyses gave nominal P < 0.05 for four PSQI components, none of which remained significant after correction for multiple comparisons. Conclusion Compared with no intervention, a 12-week 16-form Tai Chi program lowered perceived stress and improved sleep quality in late adolescents starting university, buffering the stress escalation of the academic semester, and merits multicenter testing against an active comparator.